Tag: evs

Quizzes (439) Questions (4580)

Questions Related to evs

Multiple choice evs magic with mirrors kaleidoscope uses of plane mirror reflected light can be reflected again

An object is kept between two plane mirrors inclined at an angle $120$ from each other; calculate the number of images which are formed if the object is not on the bisector/on the bisector $3$

  1. $\displaystyle \frac {3}{3}$
  2. $\displaystyle \frac {3}{2}$
  3. $\displaystyle \frac {2}{2}$
  4. $\displaystyle \frac {2}{3}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Given: An object is kept between two plane mirrors inclined at an angle 120 from each other

To find the ratio of number of images which are formed if the object is not on the bisector and on the bisector
Solution:
If there are two plane mirrors inclined to each other at an angle $\theta$, the number of images of a point object formed are determined as follows:

If $\left(\dfrac {360^\circ}\theta\right)$ is odd integer (say $m$) number of images formed
$n = m$, if the object is not on the bisector of mirrors
$n = (m – 1)$, if the object is on the bisector of mirrors.

So, when $\theta=120^\circ$, we get
$m=\dfrac {360}{120}=3$
So,
$\dfrac {\text{ number of images which are formed if the object is not on the bisector}}{\text{ number of images which are formed if the object is on the bisector}}=\dfrac {3}{3-1}=\dfrac 32$

Multiple choice evs rain: where does it come from sources of water and water cycle availability and forms of water the water cycle

Which of the following is the most important factor in balancing the amount of freshwater on earth?

  1. Water cycle

  2. Greenhouse effect

  3. Waste water treatment plant

  4. Transpiration
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water cycle is a continuous cycle in which water changes from water vapour in the atmosphere, through liquid water through condensation and precipitation and then back to water vapour through evaporation, transpiration and respiration. 

Among the given options, $A$ is the correct one. 

Multiple choice evs rain: where does it come from sources of water and water cycle availability and forms of water the water cycle

When water circulates through the water cycle it can be found in all the _________ form, at any given time somewhere on the earth.

  1. four

  2. two

  3. three

  4. six
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When water circulates through the water cycle it can be found in all the three forms, i.e., solid, liquid and gas at any given time somewhere on the earth. This continuous cycling of water in its three forms in nature keeps the total amount of water on earth constant even when the whole world is using it.

Multiple choice evs magic with mirrors lateral inversion right or left reflection at plane surface

Lateral inversion is a feature of plane mirrors, in which:

  1. The top part of the object appears to be the bottom part of the image.

  2. The left side of the object appears to be the right side of the image.

  3. Image appears to be inverted upside down and also sideways.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
$ \bf{Lateral\ Inversion} $ is the phenomenon in which when looked through a mirror, the left-hand side of an object appears as right-hand side of the image and vice versa.

Hence, the correct answer is OPTION B.